<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <h1>我是a页面</h1>
    <button class="btn1">红色</button>
    <button class="btn2">蓝色</button>
</body>
</html>
<script>
    var btn1 = document.querySelector(".btn1");
    var btn2 = document.querySelector(".btn2");

    btn1.onclick = function (){
        window.location.href = "./b.html?type=1";
    }
    btn2.onclick = function (){
        window.location.href = "./b.html?type=2";
    }


</script>